Messages in this thread | | | Date | Sat, 17 Dec 2022 01:59:57 +0100 | From | Pali Rohár <> | Subject | Re: [PATCH v2] powerpc: Pass correct CPU reference to assembler |
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On Friday 16 December 2022 12:10:48 Segher Boessenkool wrote: > On Fri, Dec 16, 2022 at 05:57:46PM +0000, Christophe Leroy wrote: > > Le 16/12/2022 à 18:18, Segher Boessenkool a écrit : > > > On Fri, Dec 16, 2022 at 09:35:50AM +0100, Christophe Leroy wrote: > > >> Today we have CONFIG_TARGET_CPU which provides the identification of the > > >> expected CPU, it is used for GCC. Use it as well for the assembler. > > > > > > Why do you use -Wa, at all for this? The compiler should already pass > > > proper options always! > > > > That's historical I guess. Comes from commit 14cf11af6cf6 ("powerpc: > > Merge enough to start building in arch/powerpc.") > > Ah. The patch moves stuff around, I thought more of it is new than it > really is. Sorry. > > It would be good to get rid of all such things that do no good and can > easily cause problems, of course, but that does not belong to this patch > of course.
Just a coincident but u-boot has similar problem... https://patchwork.ozlabs.org/project/uboot/patch/20221211141204.8153-1-pali@kernel.org/
So I agree that removal of -Wa,-mXXX is a good idea. I checked that gcc pass correct -Wa,-mXXX flag from -mcpu=YYY flag.
> > >> +cpu-as-$(CONFIG_PPC_BOOK3S_64) += $(call as-option,-Wa$(comma)-many) > > > > > > What is this for? Using -many is a huge step back, it hides many > > > problems :-( > > > > The only thing I did is removed the -Wa,-mpower4 from the line, leaving > > the remaining part. Initialy it was: > > > > cpu-as-$(CONFIG_PPC_BOOK3S_64) += $(call as-option,-Wa$(comma)-mpower4) > > $(call as-option,-Wa$(comma)-many) > > > > It was added in 2018 by commit 960e30029863 ("powerpc/Makefile: Fix > > PPC_BOOK3S_64 ASFLAGS"). There is a long explanation it the commit. > > > > Should we remove it ? > > The commit says it is a workaround for clang problems, so it needs > testing there. It also needs testing everywhere else, because as I said > it hides a lot of problems, so removing it will make a lot of sloppy > code that has crept in since 2018 scream bloody murder :-( > > > Segher
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